I have seen what is done in this video many times. I have studied internal Chinese Martial arts. I can do the things shown in this video. I'll make a video of me showing these things. I'll show up in person at one of your seminars in California and demonstrate this for you if you'd like.
GT
This type of thing is very common in Chinese internal, any good teacher will show you these things. While it can be impressive it's not what I believe Ueshiba was going for. I don't think what I see in this video will bring the world together. It does not speak "Aikido is the principle of unifying heaven, earth and humankind." or "Aikido is the way of supreme, unbounded, perfect, and inexhaustible love that binds and sustains the universe." These too are the words of the founder. As I describe Aiki, these words fit perfectly, I don't see how they apply to what I'm seeing in that video.

I am unaware of you learning IS in your studies of ICMA. I don't want to get into teachers and what they can and cannot do.
What is your exposure to several other CHINESE ICMA Master class teachers....not related to your teacher?
Lets just say that some teachers...Master level teachers from China... bounced themselves off of me when trying the things in the video I posted. Now...since that happened in public in an open room at his own seminar-and this after separating me from his lineage holding student...telling him that "I was too much for him"... How then do we think that any of this Master Class Chinese teacher's own students...ended up with IS? How would that happen?

Martial arts are filled with many excellent technicians who would not know internal power if it fell on them. THAT....is why I test for IS outside of waza or fighting ability. For example- Jujutsu both traditional and modern has some excellent players; There are some MA experts out teaching internal power, who really have no business doing so. They are very, very good at what they do and that is enough to vet them for anything they wish to market themselves as to almost everyone who has no real exposure to what IS really is.
Budd was spot on with talking about good grapplers doing some things close to internal movement. And high level jujutsu -including really good Greco Roman and BJJ can be very ghosty and fluid. For most Ma'ers when they meet and feel these guys and if they watch them win a fight...it vets...all of their rhetoric about anything they want to say.

And yet....
I continue to meet men who spent 8-15 years in China training under Masters-who are good jujutsu guys...and they have no IS.
I continue to meet men who spent 5-35 years in Japan-who are good jujutsu and weapons guys with no IS.
How do I know? Outside of their waza, they have no unusual power of any kind. They feel like any other Tom, Dick, or Harry.
Same with the Sumo video in the OP. There are "tells" that show he is not connected fully. The same can be said for Menkyo' in JMA and SHihan in various arts.
I have gotten into trouble for pointing it out, only to find out upon feel that I was spot on, or when others felt them after feeling people who really were connected THEY reported that our analysis was true.

Personally, I think everyone would have to go feel a series of ICMA master class teachers who are known to have IS before they should seriously consider that they know what it even feels like, much less do.
That leaves me with the fact that you continue to bring up your mimicing or copying what you see on film and thinking you are duplicating it. We have seen it before. LCD is not Doing "a thing" it is a quality of movement. and if you had it? You would be famous. It really that simple. It is inescapable and obvious. anyone who touched you would want to be a student as you would feel different.
I think for most people that is one area in discussing IS like this on these threads. There is no escape from one obvious fact.
If everyone has IS and it is the aiki you describe...why do they feel normal and can be tossed around?
How then do you explain those who feel different and cannot be tossed around?
Usually it is explained through their ability with "Waza."
Yet all of the famous guys who were unusual said it had nothing to do with waza
When someone tells me they can do these things I simply ask
Why are you not famous?

I agree on Ueshiba's comments. However, his body displayed a power that impressed people. All of the interviews and stories we fawn over....over and over again, talk of men NOT being impressed by his waza...but of touching and feeling his body movement.
Again...and to repeat, just as I said "I test bodies and not letting someone hide behind jujutsu"....the Majority of the interviews we see focus on people commenting on Ueshiba's "unusual power" His internal strength...not his jujutsu.
Didn't he say...Aiki had nothing to do with waza.
Didn't he quote Chinese IP methods?